JP2001018436A - Image-forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably form images by surely preventing through holes from clogging at a control plate where an array of the through holes for passing toner is formed. SOLUTION: A vibration generation member 6 is set on a control plate 17 to extend parallel to a developer pass hole array 17g. The vibration generation member 6 is constituted of a vibration plate 6a, a vibrator 6b formed of a piezoelectric element and a rigid rod 6c for regulating extension and contraction of the vibrator 6a in an X direction to apply traverse waves of an equal phase in a direction of the array (X direction) to each of developer pass holes 17a of the control plate 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a facsimile, and a printer.
The present invention relates to an image forming apparatus that forms an image by causing a powdery developer to fly by the action of an electric field or the like.

[0002]

2. Description of the Related Art Conventionally, there is known an image forming apparatus in which a powdery developer is caused to fly by the action of an electric field or the like to form an image on recording paper. Generally, this type of apparatus records a head in which toner as a developer is stored, an intermediate image holding belt disposed opposite to the head, and an image formed on the intermediate image holding belt. It comprises a transfer unit for transferring the image on paper and a fixing unit for fixing the image on the recording paper.

As shown in FIG. 16, a sleeve 1 carrying toner 100 charged to a negative charge is provided on a head.
11 and the toner 100 carried on the sleeve 111.
And a control plate 117 for controlling the flight of the aircraft. On the control plate 117, a plurality of developer passage holes 117a are arranged in a direction perpendicular to the plane of FIG. 16 to form a row of developer passage holes. The control electrodes 117b and 117 are provided on the control plate 117 so as to surround the respective developer passage holes 117a.
d is provided. Then, the intermediate image holding belt 102
On the opposite side of the sleeve 111 with respect to the sleeve 111, a back electrode 123 is disposed at a position facing the developer passage hole array of the control plate 117.

In the above-described image forming apparatus, the control electrode 117b
, An electric field is generated near the developer passage hole 117a, and the toner 100 carried on the sleeve 111 flies by the action of the electric field. The flying toner 100 passes through the developer passage hole 117a,
It is pulled by the electric field formed by the back electrode 123 and adheres to the intermediate image holding belt 102. Therefore, the toner 100 on the sleeve 111 passes through the developer passage hole 117a surrounded by the control electrode 117b to which the voltage is applied, but does not pass through the developer passage hole surrounded by the control electrode to which the voltage is not applied. The flying of the toner 100 can be controlled by controlling the voltage applied to the control electrode 117b. That is, a desired image is formed on the intermediate image holding belt 102 by selectively applying a voltage to the control electrode 117b around the predetermined developer passage hole 117a in accordance with an external image signal. Become. Thereafter, the toner 100 adhered to the intermediate image holding belt 102 is conveyed by the intermediate image holding belt 102, and is transferred onto recording paper by a transfer unit (not shown). Then, the transferred image is fixed by a fixing unit (not shown).
And the recording on the recording paper is completed.

[0005]

However, in the above-mentioned conventional image forming apparatus, as the image formation is continued, the area around the sleeve 111 side of the developer passage hole 117a, the inner wall of the developer passage hole 117a, or The toner 100 may accumulate around the passage hole 117a on the side of the intermediate image holding belt 102, and the accuracy of image formation may be reduced. Further, there is a possibility that the developer passage hole 117a is finally closed by the toner 100.

As means for solving such a problem, for example, as disclosed in Japanese Patent Application Laid-Open No. 4-80053, a control plate is provided with a vibration mechanism. By employing such a configuration, the control plate always vibrates. Therefore, it is expected that the toner 100 does not adhere to the control plate, and that even if it adheres, it is immediately removed.

However, it is difficult to obtain a practically sufficient effect only by vibrating the control plate as described above, and further improvement has been desired for practical use. Further, the above configuration merely vibrates the control plate, and no consideration is given to the vibration waveform. Therefore, when the vibration waveform is a standing wave, the amplitude of the node becomes small, so that the cleaning ability may be uneven (a region where the toner is easily removed and a region where the toner is difficult to remove appear alternately). There is a problem that the toner cannot be removed satisfactorily as a whole.

The present invention has been made in view of such circumstances, and an object of the present invention is to reliably prevent blocking of a developer passage hole due to accumulation of a developer, thereby achieving stable image formation. Is to make it happen.

[0009]

In order to achieve the above-mentioned object, the present invention is directed to a developer passage control member in which the developer passage hole portions have the same phase in the row direction of the developer passage hole array. It was decided to apply a phase vibration.

Specifically, the image forming apparatus according to the present invention comprises: a developer carrying means for carrying the developer while carrying the developer;
A developer provided between the developer carrying means and the image receiving means, having at least one row of developer passing holes in which a plurality of developer passing holes are arranged, and a developer conveyed by the developer carrying means; A developer passage control member that controls the developer to fly through a predetermined developer passage hole in accordance with an image signal and adhere to the image receiving means; and removes the developer adhered to the developer passage control member. Vibrating means for vibrating the developer passage control member so as to separate the developer passage control member, wherein the vibration means has the same phase in each developer passage hole portion of the developer passage control member. It is configured to apply vibration.

According to the above, vibrations of the same phase, that is, vibrations having the same phase in the row direction of the row of the developer passing holes are applied to the respective developer passing hole portions of the developer passing control member, and the vibrations along the row direction are provided. Irregularities in cleaning performance are prevented. Accordingly, the developer is uniformly removed, the blocking of the developer passage hole due to the accumulation of the developer is reliably prevented, and stable image formation is realized.

The vibrating means extends in parallel with the row direction of the developer passage hole row and is fixed to the surface of the developer passage control member, and extends in parallel with the row direction so as to overlap the diaphragm. The piezoelectric device may further include a piezoelectric element fixed to a surface of the vibration plate opposite to a surface in contact with the developer passage control member, and a restricting member that restricts expansion and contraction of the piezoelectric element in the row direction.

According to the above, when a voltage is applied to the piezoelectric element, the piezoelectric element bends and deforms together with the diaphragm. In this case, since the expansion and contraction of the piezoelectric element in the above-mentioned row direction is regulated by the restricting body, the diaphragm bends exclusively in the direction orthogonal to the above-mentioned row direction. As a result, the vibration wave transmitted from the vibration plate to the developer passage control member becomes a vibration wave having a uniform phase in the row direction, and the same phase vibration is applied to each developer passage hole portion of the developer passage control member. Is done.

Another image forming apparatus according to the present invention is provided with a developer carrying means for carrying and transporting a developer, and a plurality of developer passing holes provided between the developer carrying means and the image receiving means. The image receiving device has at least one row of developer passage holes arranged in a row, and flies the developer conveyed by the developer carrying means so as to pass through a predetermined developer passage hole according to an image signal. An image forming apparatus comprising: a developer passage control member configured to control the developer passage control member to adhere to the unit; and a vibration unit configured to vibrate the developer passage control member so as to detach the developer adhered to the developer passage control member. A forming device,
The vibrating means includes a vibration transmission body extending in parallel with the row direction of the developer passage hole row and fixed to a surface of the developer passage control member, and the vibration transmission body extending from one end to the other end of the vibration transmission body. A vibration generating unit that applies vibration to one end of the vibration transmitting body so as to generate a vibration wave traveling in a direction parallel to the direction, and a vibration that controls the vibration so that the vibration wave in the vibration transmitting body becomes a non-standing wave. And a control unit.

According to the above, non-stationary vibration waves propagate to the vibration transmitting body extending in parallel with the developer passage hole array. As a result, the vibration wave transmitted from the vibration transmitting body to the developer passage control member becomes a vibration wave having a uniform phase in the row direction of the developer passage hole row. In-phase vibration is applied. Accordingly, the developer is uniformly removed, the blocking of the developer passage hole due to the accumulation of the developer is reliably prevented, and stable image formation is realized.

The vibration control section includes a vibration absorber provided at the other end of the vibration transmitting body so that the vibration applied to the one end of the vibration transmitting body from the vibration generating section is absorbed at the other end of the vibration transmitting body. Means may be provided.

According to the above, the vibration wave travels from one end to the other end of the vibration transmitting body, but since this vibration wave is not reflected at the other end, it becomes a non-stationary wave.

The vibration control section includes a clamp means for sandwiching the other end of the vibration transmitting body while shifting the clamp position so as to change the reflection position of the vibration at the other end of the vibration transmitting body with time. Is also good.

According to the above, the vibration wave traveling from one end of the vibration transmitting body toward the other end is reflected at the clamp position at the other end. When the traveling wave and the reflected wave overlap, a standing wave is generated on the vibration transmitting body. However, since the clamp means changes the clamp position with time, the vibration wave formed on the vibration transmitting body is a standing wave instantaneously, but becomes non-stationary over time, and is substantially non-stationary. It becomes a standing wave.

The vibration control section may include auxiliary vibration means for slightly disturbing the vibration from the vibration generating section in the vibration transmitting body.

According to the above, the vibration from the vibration generator in the vibration transmitting body is minutely disturbed by the auxiliary vibrating means. As a result, the vibration wave in the vibration transmitter becomes a non-standing wave.

The developer passage control member is provided on the side opposite to the vibration transmitting body across the developer passage hole array so as to form a reflection end for reflecting vibration from the vibration transmitting body. Is preferably in line contact with the developer carrying means in parallel with the row direction.

According to the above, the vibration transmitted from the vibration transmitting body to the developer passage control member advances toward the developer passage hole array. Then, the vibration wave that has passed through the developer passage hole array is reflected at the reflection end, and the traveling wave and the reflected wave overlap to form a standing wave in a direction orthogonal to the row direction of the developer passage hole array. Therefore, if the portion of the developer passage hole or its vicinity does not become a node of the standing wave, the portion will always vibrate, and the developer that is to be deposited in or around the developer passage hole will not be effective. Will be removed.

Preferably, a spacer means is provided at the reflection end of the developer passage control member, and the developer passage control member is in contact with the developer carrying means via the spacer means.

According to the above, the traveling wave is accurately and reliably reflected by the developer passage control member, and a good standing wave is easily formed.

Preferably, the spacer means extends along the row of developer passage holes.

According to the above, the standing wave is more easily formed.

Distance L1 between developer passage hole array and reflection end
Is L1 <L with respect to the wavelength λ of the vibration wave in a direction orthogonal to the row direction of the developer passage hole row in the developer passage control member.
Preferably, it is set to be λ / 2.

According to the above, a large displacement is given to the developer passage hole, and the developer is efficiently removed.

The vibrating means may include a standing wave having a node at the reflection end and an antinode at the antinode of the developer passage control member. It is preferable to provide a vibration that gives the following.

According to the above, the largest displacement is given to the developer passage hole, and the developer is removed more efficiently.

If the distance L2 between the vibration transmitting body and the reflection end is too short, a standing wave is not easily formed, and the vibration efficiency is reduced. If the distance L2 is shorter than λ / 4, the nodes vibrate, and the developer passage control member, the spacer means, the sleeve, etc. may be worn or heat may be generated.

Therefore, the distance L2 between the vibration transmitting body and the reflection end is defined as L2> L with respect to the wavelength .lambda.
Preferably, it is set to be λ / 4.

[0034]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 shows an image forming apparatus according to Embodiment 1 of the present invention, in which 1, 1,... Represent particulate toner 19 as a developer (FIGS. 2 and 3). See)). Reference numeral 11 denotes a sleeve 11 as a developer carrying means, reference numeral 2 denotes an intermediate image holding belt as an image receiving means, reference numeral 3 denotes a transfer device for transferring an image formed on the intermediate image holding belt 2 to recording paper 5, and reference numeral 4 denotes a recording paper 5. Is a fixing device for fixing the image transferred onto the recording paper 5. The image forming apparatus is provided with four heads 1, and each head 1 stores toner 19 of each color of yellow, magenta, cyan, and black. Thus, the present image forming apparatus is configured to be able to form a color image.

Each of the toners 19 is made of styrene acrylic, polyethylene, or the like, and has an average particle diameter of 10 μm.
m. In addition, such a measurement of the diameter can be performed by a small hole passage method (Multisizer manufactured by Coulter Inc.).

The intermediate image holding belt 2 is an endless type belt, and is wound around a belt driving roller 21 for driving the intermediate image holding belt 2 and a ground roller 22. On the back side of the intermediate image holding belt 2, that is, on the side opposite to the front side facing the sleeve 11, a back electrode 23 and a power supply 24 are provided. Back electrodes 23, 23, ...
Are disposed at positions opposing each of the heads 1, 1,.... In addition, a belt cleaning 25 is disposed on the intermediate image holding belt 2 at a position facing the belt driving roller 21. The belt cleaning 25 presses a portion of the intermediate image holding belt 2 on the front side of the head 1, and removes unnecessary toner and stains on the intermediate image holding belt 2 before image formation.

As the intermediate image holding belt 2, for example, a belt obtained by dispersing conductive carbon in polycarbonate having a thickness of about 150 μm may be used. The circumference may be set to about 340 mm for A4 paper, for example.
As the belt driving roller 21 and the ground roller 22, a roller having a diameter of about 25 mm to 30 mm can be suitably used. Further, as the back electrode 23, a metal plate or a film in which a conductive filler is dispersed in a resin can be suitably used. The voltage applied to the back electrode 23 is preferably about 500 V to 2000 V, and may be set to, for example, 1000 V.

The transfer device 3 includes a transfer roller 31 disposed so as to be opposed to the ground roller 22, and the transfer roller 31 is configured to be able to freely contact and separate from the ground roller 22. The transfer roller 31 is provided with a transfer power supply 32. When a voltage is applied to the transfer roller 31 by the transfer power supply 32, an electric field is generated between the transfer roller 31 and the ground roller 22. The toner on the image holding belt 2 is drawn to the recording paper 5 side. The transfer device 3 moves the intermediate image holding belt 2 and the recording paper 5 between the transfer roller 31 and the ground roller 22.
The image on the intermediate image holding belt 2 is transferred to the recording paper 5 by bringing the two into close contact.

The transfer roller 31 is formed by winding a urethane sponge around a shaft core having a diameter of, for example, 8 mm, and its outer diameter is set to about 20 mm, and its resistance value is 5 mm.
It is set to about 10 ⁷ Ω when 00V is applied.

The fixing device 4 is configured by disposing a fixing roller 41 and a pressure roller 42 facing each other. A heat source 41 a is disposed inside the fixing roller 41. The heat generated by the heat source 41a keeps the peripheral surface of the fixing roller 41 at a high temperature. As described above, the fixing device 4 applies heat to the recording paper 5 by applying heat from the fixing roller 41 and pressure from the pressing roller 42 to the fixing roller 41 so that the toner is melted and fixed to the recording paper 5. It is configured.

As shown in FIG. 2, each head 1 has a substantially rectangular box-shaped frame 16 having an opening on the intermediate image holding belt 2 side. In the frame 16, a sleeve 11, a toner regulating blade 12 disposed on the inner side of the frame 16 on the inner side of the frame 11 so as to contact the peripheral side surface of the sleeve 11, and a sleeve 11 on the inner side of the frame 16. A toner supply roller 13 disposed to face the sleeve 11, a hopper 14 formed inside the sleeve 11 for storing toner 19, and a toner hopper 14 disposed in the hopper 14 to stir the toner 19. And a stirring member 15 are provided.

The sleeve 11 is formed in a cylindrical shape, and conveys while carrying the toner 19 by rotating counterclockwise in FIG. 2 (see the arrow in the figure). In this embodiment, the sleeve 11 is grounded (see FIG. 1), but a DC or AC voltage may be applied to the sleeve 11. The sleeve 11 can be formed of, for example, a metal such as aluminum or iron, an alloy, rubber, or the like. Also, its outer diameter is 16mm ~ 20mm,
The thickness may be about 1 mm. Also, sleeve 1
The rotation speed of 1 is, for example, 20 mm to 400 mm / sec.
Should be set to.

The toner regulating blade 12 is
A toner layer is formed thereon, and the toner 19 is charged by friction. The toner layer is arranged so as to abut against the rotation direction of the sleeve 11 in the counter direction. Specifically, the toner regulating blade 12 is configured to charge the toner 19 to a negative polarity, and is configured to form one toner layer on the sleeve 11. Such a toner regulating blade 12 is formed by attaching an elastic member such as a urethane rubber sheet to a phosphor bronze plate material, for example.

The supply roller 13 supplies the toner 19 in the hopper 14 to the sleeve 11, and is configured to contact the sleeve 11 and rotate in a direction opposite to the sleeve 11 (clockwise in FIG. 2). I have. The biting amount of the supply roller 13 into the sleeve 11 is preferably, for example, about 0.1 mm to 0.2 mm. As the supply roller 13, for example, a roller obtained by winding a synthetic rubber such as a urethane sponge around a metal shaft can be suitably used, and its outer diameter may be set to, for example, about 12 mm.

With the above configuration, the toner 19 in the hopper 14 is agitated by the agitating member 15, and then the supply roller 13 and the sleeve 11 are rotated by each other, so that the toner 19 is carried on the surface of the sleeve 11. The carried toner 19 is transferred to the toner regulating blade 12
As a result, the excess is removed, while the one carried on the sleeve 11 is negatively charged.

As shown in FIG. 3, the opening of the frame 16 in the head 1 is provided with a developer passage control member as a developer passage control member.
Flexible Print Circuit
Circuit, hereinafter referred to as FPC)
Are disposed so as to face the sleeve 11.
In the insulating portion 17c of the control plate 17, a plurality of developer passage holes 17a through which the toner 19 passes are formed in a direction orthogonal to the paper surface of FIG. 3, and as a result, a developer passage hole array 17g is formed (see FIG. 3). (See FIG. 4). A control electrode 17b for generating an electric field for causing the toner 19 carried on the sleeve 11 to fly is disposed on the surface around the developer passage hole 17a and on the sleeve 11 side. On the other hand, on the surface around the developer passage hole 17a and on the side opposite to the sleeve 11 side (the side of the intermediate image holding belt 2), the toner passing through the developer passage hole 17a is prevented from spreading and flying. A guard electrode 17d for generating the electric field is provided. The control electrode 17b and the guard electrode 17d are coated with coating resins 17e and 17f, respectively.

As the control plate 17, for example, an insulating portion 17c
Is preferably formed of a polyimide resin, and its thickness may be set to 10 μm to 70 μm. The diameter of the developer passage hole 17a is 50 μm or more.
It can be suitably formed by an opening of 200 μm,
In the present embodiment, the diameter is set to 130 μm. The thickness of the control electrode 17b and the guard electrode 17d is set to, for example, 10 μm, and the thickness of the coating resins 17e and 17f is set to, for example, 1 μm to 2 μm.

The control plate 17 has viscoelasticity because the insulating portion 17c is made of polyimide resin. Although not shown, the control plate 17 has one end fixed and the other end pulled and arranged by an elastic member such as a spring member. For this reason, the control plate 17 easily bends and deforms, and is easily vibrated by receiving the restoring force of the spring member.

The voltage applied to the control electrode 17b may be set to, for example, 300 V or less.
May be set to, for example, -100V.

As shown in FIG. 4, the developer passage holes 17a,
Are arranged in a row along the rotation axis direction of the sleeve 11, and the plurality of developer passage holes 17a, 1
The developer passage hole array 17g is formed by 7a,. Further, the control plate 17 is provided with a vibration generating member 6 extending in parallel with the row direction of the developer passage hole row 17g (X direction in FIG. 4; hereinafter, also simply referred to as “row direction”).
The vibration generating member 6 corresponds to a vibration means in the present invention, and is formed in a rod shape or a plate shape, and is adhered and fixed to the control plate 17 as described below. Such bonding may be performed by, for example, thermocompression bonding.

The vibration generating member 6 generates a wave that causes the control plate 17 to bend and deform, for example, a transverse wave. In the present embodiment, the vibration generating member 6 is
And a vibrator 6a. The diaphragm 6b is provided with the developer passage hole row 1
It extends parallel to the 7 g column direction and is adhered to the surface of the control plate 17. The vibrator 6a extends in parallel with the row direction of the developer passage hole row 17g so as to overlap the vibrating plate 6b, and is adhered to the surface of the vibrating plate 6b. 17g of developer passage hole row
Vibrator 6a and diaphragm 6 in a direction orthogonal to
The lengths with b are equal to each other. As the diaphragm 6b, for example, stainless steel having a plate width of about 5 mm and a plate thickness of about 0.3 mm can be suitably used, and as the vibrator 6a, for example, a piezoelectric element (PZT) can be suitably used.

Further, on the surface of the vibrator 6a, the vibrator 6a
A rigid rod 6c extending in the column direction is affixed as a restricting body for restricting expansion and contraction in the column direction. As the rigid rod 6c, a material having a high Young's modulus such as stainless steel can be suitably used. Thereby, the bending of the control plate 17 in the column direction is suppressed. As a result, a plane wave having the same phase in the column direction and the same phase is applied to each developer passage hole 17g of the control plate 17. Has become.

That is, as shown in FIG. 5, due to the expansion and contraction of the vibrator 6a in the Y direction, that is, the expansion and contraction in the direction of the arrow A, the difference in rigidity between the vibrator 6a and the diaphragm 6b causes
Causes deflection in the direction of arrow B (Z direction which is a direction orthogonal to the X direction and the Y direction). However, since the bending in the column direction is restricted by the rigid rod 6c, the bending amount in the B direction is equal at an arbitrary cross section in the column direction. Therefore, by periodically expanding and contracting the vibrator 6a, the control plate 17 periodically repeats the flexural deformation, and as a result, it is possible to generate in-phase vibration at any point in the row direction. Becomes

If the vibration frequency is too high, the toner 19
And the control plate 17 vibrate integrally, and the toner 19
It is not easy to break the bond between the interface and the control plate 17 and the attached toner cannot be removed satisfactorily. Thus, the vibration of the vibration generating member 6 is preferably a sine wave having a frequency of 1 MHz or less, for example, 20 MHz.
A sine wave of kHz may be used.

Next, an image forming operation in the present image forming apparatus will be described.

First, when a voltage of 300 V is applied to the control electrode 17b by an external image signal, the control electrode 1b
An electric field is formed between the sleeve 7 b and the sleeve 11, and the electric field causes the toner 19 carried on the sleeve 11 to form the control plate 1.
It is pulled to the side 7 and flies from the sleeve 11. Then, the toner 19 pulled by the electric field passes through the developer passage hole 17 a of the control plate 17. Developer passage 1
The toner 19 that has passed through 7a is guided toward the intermediate image holding belt 2 by the electric field formed by the back electrode 23, and adheres to the intermediate image holding belt 2.

On the other hand, when a voltage of -100 V is applied to the control electrode 17b, the electric field is not formed between the control electrode 17b and the sleeve 11, so that the toner 19 carried on the sleeve 11 is carried on the sleeve 11. Will remain. Therefore, when a voltage of −100 V is applied to the control electrode 17b, the toner 19 does not pass through the developer passage hole 17a and adhere to the intermediate image holding belt 2.

As described above, each developer passage hole 1 of the head 1
The voltage applied to the control electrode 17b provided on the intermediate image holding belt 7a is controlled, and the toner 19 adheres to the intermediate image holding belt 2 as appropriate.
An image corresponding to the image signal is formed.

Then, from the end of one unit of image forming processing to the time of moving to the next image forming processing (hereinafter referred to as “sheet interval”).
), A voltage is applied to the vibrator 6a of the vibration generating member 6, and the vibration generating member 6 vibrates. Then, this vibration is transmitted to the control plate 17 via the diaphragm 6b. In addition,
Under the condition that the vibration of the vibration generating member 6 is small and the image forming operation is not hindered, the vibration generating member 6 may be vibrated not only between the sheets but also during the image formation. is there.

Since the vibrations generated by the vibration generating member 6 have the same phase in the column direction (X direction), the control plate 17 applies a plane wave having the same phase in the column direction to the direction orthogonal to the column direction (Y direction). To be propagated. Therefore, the vibration waves having the same phase in the column direction propagate through the respective developer passage holes 17a.
As a result, each developer passage hole 17 of the developer passage hole row 17g
can be uniformly vibrated, and clogging of the passage holes 17a, 17a,... can be uniformly prevented or eliminated.

In this embodiment, the case where the developer passage hole row 17g is one row is shown, but the developer passage hole row 17g
Is not limited to one row, but may be composed of two rows or more.

(Embodiment 2) Hereinafter, Embodiment 2 of the present invention will be described with reference to the drawings. Since the basic operation and operation are the same as those of the first embodiment, in the following description, only different portions will be mainly described.

As shown in FIG. 6, in this embodiment, a vibration transmitting member 63 is provided in parallel with the developer passage hole array 17g. The vibration transmission member 63 is formed in a rod shape or a plate shape, and is adhered and fixed to the control plate 17.

At one end of the vibration transmitting member 63, a vibrating body 60 having a vibrator 61 and an amplifier (horn) 62 is provided as a vibration generating section. As the vibrator 61, for example, a bolted Langevin type vibrator can be suitably used. The vibrator 61 is attached to the amplifier 62. The amplifier 62 is formed so that its cross-sectional area decreases as it goes downward, and is configured to concentrate the vibration energy of the vibrator 61 and transmit it to the vibration transmission member 6. At the other end of the vibration transmitting member 63, a vibration absorber 64 is provided so as to absorb the wave starting from the vibrator 61 and not to reflect the vibration wave.

The vibration transmitting member 63 may have any rigidity capable of transmitting vibration without absorbing it.
For example, it may be formed of metal. Specifically, for example, stainless steel can be suitably used. Further, the plate width may be set to 5 mm and the plate thickness may be set to about 0.2 mm.
The amplifier 62 may be formed of any material having a rigidity capable of transmitting vibration without absorbing vibration, and may be formed of, for example, metal. Specifically, it is particularly preferable to use, for example, stainless steel or aluminum because the molding is easy. For example, silicon rubber can be suitably used as the vibration absorber 64, but the configuration of the vibration absorber 64 is not limited to this.

The frequency of the vibration wave of the vibrator 61 is 1
A sine wave of MHz or less is preferable, and its frequency may be, for example, 20 kHz. This is because, when the vibration frequency increases, the toner 19 and the control plate 17 vibrate in the same manner, and it is not easy to cut off the coupling between the toner and the control plate 17 at the interface.

Next, an image forming operation of the image forming apparatus according to the present embodiment will be described.

In this image forming apparatus, a voltage is applied to the vibrator 61 between the sheets, and the vibration of the vibrator 61 is transmitted to the control plate 17 via the amplifier 62 and the vibration transmitting member 63. Note that, as in the first embodiment, the timing of application to the vibrator 61 is not limited to the time between paper sheets, and may be during image formation.

Since the vibration transmitting member 63 is elongated in the row direction,
It is easy to bend in the column direction. Therefore, the vibration of the vibrating body 60 propagates as a transverse wave in the vibration transmitting member 63. However, since the transverse wave is absorbed by the vibration absorber 64 at the other end of the vibration transmitting member 63, a reflected wave from the other end is not generated. As a result, since only a traveling wave in one direction is formed on the vibration transmitting member 63, no standing wave along the row direction on the developer passage hole row 17g is generated. Therefore, according to the present embodiment, the developer passage holes 17a, 17a,... Of the developer passage hole row 17g can be vibrated uniformly, and the passage holes 17a, 17a,. Or can be eliminated.

The vibration absorber 64 is, as shown in FIG.
It may be a combination of the vibration absorbing plates 71, 71 and the rigid plates 72a, 72b. As the vibration absorbing plate 71, any material having viscoelasticity sufficient to sufficiently attenuate vibration may be used, and for example, silicon rubber can be suitably used.
As described above, sufficient vibration damping can be obtained by sandwiching the vibration absorbing plate 71 between the rigid plates 72a and 72b and uniformly bringing the vibration absorbing plate 71 into close contact with the vibration transmitting member 63. When a material having a sufficient thermal conductivity, for example, aluminum is used as the material of the rigid plates 72a and 72b, heat generated from the vibration absorbing plate 71 in the vibration absorbing process can be easily released to the outside. Further, as shown in FIG. 7 (c), a radiation fin 73 may be provided on the rigid plate 72a in order to enhance heat radiation. Further, for example, silicon grease may be applied between the vibration absorbing member 71 and the vibration transmitting member 63 in order to promote the transmission of vibration from the vibration transmitting member 63 to the vibration absorbing member 71. Also, the rigid plates 72a and 72b are tightened with screws,
An appropriate pressure may be applied to the vibration absorbing plate 71. In order to promote heat conduction from the vibration absorbing plate 71 to the rigid plates 72a and 72b, for example, silicon grease may be applied between the vibration absorbing plate 71 and the rigid plate 72. The length of the attenuation section of the vibration transmitting member 63 by the vibration absorber 64 is preferably at least as long as a half wavelength of the flexural wave on the vibration transmitting member 63, and is at least as long as four wavelengths of the flexural wave. Is particularly preferred.

Incidentally, also in the present embodiment, the developer passage hole row 17g may be composed of two rows or more.

(Embodiment 3) Next, Embodiment 3 of the present invention will be described.

As shown in FIG. 8, also in this embodiment, a vibration transmitting member 63 is arranged in parallel with the developer passage hole array 17g. The vibration transmitting member 63 is formed in a rod shape or a plate shape, and is adhered and fixed to the control plate 17. As in the second embodiment, a vibrating body 6 having a vibrator 61 and an amplifier 62 is provided at one end of the vibration transmitting member 63.
0 is provided.

In this embodiment, the vibration transmitting member 6
At the other end of 3, a clamp mechanism 65 is provided as vibration condition changing means for changing the mechanical or geometric condition of the vibration. The clamp mechanism 65 sandwiches the vibration transmitting member 63 during the vibration by the vibrator 61 and appropriately changes the sandwiching position (clamp position) along the longitudinal direction of the vibration transmitting member 63 to reflect the bending wave. This is to move the point. The clamp mechanism 65 extends in the longitudinal direction of the vibration transmitting member 63, that is,
It is configured to be movable along the column direction of g. As a material of the clamp portions 65a and 65b of the clamp mechanism 65, a material having rigidity enough to reliably reflect a bending wave and viscoelasticity enough to suppress generation of abnormal noise at the time of clamping is preferable. Coated aluminum or the like can be suitably used. FIG.
Although the tip portions of the clamp portions 65a and 65b shown in (1) and (2) are sharp, the shape of the clamp mechanism 65 may be any shape as long as the shape can securely support the vibration transmitting member 63. Needless to say, the shape may include a curved surface.

Next, the operation of the image forming apparatus according to this embodiment will be described.

Also in this embodiment, a voltage is applied to the vibrator 61 between the sheets, and the vibration of the vibrator 61 is transmitted to the control plate 17 via the amplifier 62 and the vibration transmitting member 63. It is to be noted that the timing of application to the vibrator 61 is not limited to the time between paper sheets, and may be during image formation, as in the first or second embodiment.

The bending wave on the vibration transmitting member 63 starts from one end where the vibrating body 60 is provided, and is reflected at the other end where the clamp mechanism 65 is provided. At this time, a standing wave is generated by superposition of the incident wave and the reflected wave. The position of the node of the standing wave depends on the reflection condition (boundary condition) of the end point and the vibration transmitting member 63.
It depends on the length, thickness, or vibration frequency. Therefore, in the present embodiment, by changing the clamp position of the vibration transmitting member 63 by the clamp mechanism 65 during the vibration, the reflection condition of the end point or the vibration transmitting member 6 is changed.
At least one of the vibration lengths 3 is changed. Thus, the positions of antinodes and nodes of the standing wave are appropriately changed, and the vibration wave of the vibration transmitting member 63 can be made a non-standing wave. As a result, the developer passage holes 17a, 17a,... Of the developer passage hole array 17g can be vibrated uniformly, and the clogging of the passage holes 17a, 17a,. . In addition, when the vibration is applied by the resonance system, the resonance frequency changes with the change of the vibration condition.
The resonance frequency may be tracked by inserting a matching circuit (not shown) in a drive circuit (not shown) of the vibrator 61, and control according to the resonance frequency may be performed.

Incidentally, also in the present embodiment, the developer passage hole row 17g may be composed of two or more rows.

(Embodiment 4) Next, Embodiment 4 of the present invention will be described.

As shown in FIG. 9, also in this embodiment, a vibration transmitting member 63 is arranged in parallel with the developer passage hole array 17g. The vibration transmission member 63 is formed in a rod shape or a plate shape, and is adhered and fixed to the control plate 17. A vibrator 61 and an amplifier 62 are provided at one end of the vibration transmitting member 63, and a vibrating body 60 is formed.

In this embodiment, the vibration transmitting member 6
At the other end of 3, an auxiliary vibration device 66 is provided. The auxiliary vibration device 66 may be any device capable of disturbing the vibration from the vibrator 61. For example, the PZT plate 6 shown in FIG.
6a and 66b. In order to prevent the PZT plates 66a, 66b from being broken by self-strain during vibration, the PZT plates 66a, 66b
b may be clamped by the rigid plates 66c and 66d. Incidentally, 66e is a power supply for supplying an applied voltage to the PZT plates 66a and 66b. Rigid plates 66c, 66
As a material of d, any material can be used as long as it exerts a sufficient load on the PZT plates 66a and 66b, and for example, aluminum can be suitably used. Although not shown, an appropriate load may be applied to the PZT plates 66a and 66b by further tightening the rigid plates 66c and 66d with fastening means such as screws.

Next, the operation of the image forming apparatus will be described.

Also in this embodiment, a voltage is applied to the vibrator 61 between the sheets, and the vibration of the vibrator 61 is transmitted to the control plate 17 via the amplifier 62 and the vibration transmitting member 63. The application timing is not limited to the time between sheets, and may be during image formation.

The flexural wave on the vibration transmitting member 63 starts at one end where the vibrating body 60 is provided and is reflected at the other end where the auxiliary vibrating device 66 is provided. A standing wave is generated by the superposition. However, in the present embodiment, since the micro-vibration is applied by the auxiliary vibration device 66, the vibration from the vibrator 61 is disturbed, and the antinodes and nodes of the standing wave do not stay at a certain place but move appropriately. become. Therefore, the developer passage holes 17a, 17a,... Of the developer passage hole row 17g can be uniformly vibrated, and the clogging of the passage holes can be uniformly prevented or eliminated.

It is preferable that the frequency of the vibrator 61 and the frequency of the auxiliary vibrating device 66 are not close to each other in order to efficiently perform the vibration disturbance effect of the auxiliary vibrating device 66. For example, the frequency of the vibrator 61 is set to 40 kHz.
By setting the frequency of the auxiliary vibration device 66 to about 55 kHz, the generation of standing waves can be efficiently prevented.

Incidentally, also in this embodiment, the developer passage hole row 17g may be composed of two or more rows.

(Embodiment 5) As shown in FIGS. 11 and 12, the embodiment 5 is different from the apparatus of the embodiment 1 in that the deflection propagated from the vibration generating member 6 toward the developer passage hole array 17g. A reflection member 7 for reflecting a wave is provided.

The reflection member 7 is formed of a plate-like or rod-shaped member extending in parallel with the developer passage hole array 17g, and is provided on the control plate 17 on the opposite side of the vibration generation member 6 across the developer passage hole array 17g. Glued in place. That is, similarly to the vibration generating member 6, the reflecting member 7 extends along the rotation axis direction of the sleeve 11, and the developer passing hole row 17
g, the vibration generating member 6 and the reflecting member 7 are arranged in parallel with each other.

The reflecting member 7 has only to have a rigidity capable of reflecting the vibration wave without absorbing the vibration, and is formed of, for example, a metal plate such as stainless steel.
mm, and the plate thickness is set to about 0.2 mm.

In the present embodiment, the vibration wave propagating from the vibration generating member 6 to the developer passage hole row 17g crosses the developer passage hole row 17g, and the side end (vibration wave reflection end) 7a of the reflection member 7
, The light is reflected by the vibration wave reflection end 7a. As a result, as shown in FIG. 13, the traveling wave from the vibration generating member 6 and the reflected wave from the reflecting member 7 overlap with each other, so that the vibration wave reflecting end 7 a is provided between the reflecting member 7 and the vibration generating member 6. Is a nodal standing wave s (shown by a two-dot chain line in FIG. 13)
Is formed.

Here, the vibration conditions of the vibration generating member 6, the distance between the vibration generating member 6 and the developer passage hole array 17g,
The distance between the developer passage hole array 17g and the reflection member 7 and the like,
If the portions of the developer passage holes 17a of the control plate 17 or the vicinity thereof are set so as not to become nodes of the standing wave s, the portions will always vibrate.
It is possible to effectively prevent the toner 19 that has not passed through 7a from adhering to the inside of the passage hole 17a or its peripheral edge. In addition, since the above-described portion constantly vibrates, even if the toner 19 adheres, the adhered toner 19 is easily detached easily.
9 can be reliably prevented.

Therefore, for example, the distance L1 between the vibration wave reflecting end 7a and the center line of the developer passage hole array 17g is set so as to satisfy L1 <λ / 2, where λ is the wavelength of the standing wave s. Good. By doing so, the developer passage hole row 1
The 7g portion can be constantly vibrated. Also, L1 =
If λ / 4 is used, the portion of the developer passage hole row 17g is a standing wave s
This is particularly preferable because the amplitude of the portion can be maximized.

The vibration wave reflecting end 7a and the vibration generating member 6
Is preferably set to satisfy L2> λ / 4. This is because if the distance L2 is less than or equal to λ / 4, the standing wave s is hardly formed, and the vibration wave reflecting end 7a vibrates, generating heat or the abrasion of the reflecting member 7 at that portion. Because In addition,
It is particularly preferable that the distance L2 is set so as to satisfy L2> 3λ / 4.

In the above embodiment, the vibration generating member 6 of the first embodiment is used as the vibration means. However, the vibration member 60 and the vibration transmitting member 63 of the second to fourth embodiments may be used. Of course.

(Sixth Embodiment) As shown in FIG. 14, in the sixth embodiment, the control plate 17 is brought into contact with the sleeve 11 instead of providing the reflecting member 7 as in the fifth embodiment. .

In this embodiment, the control plate 17 has a circular shape such that the portion of the developer passage hole 17g is convex toward the intermediate image holding belt 2 (that is, the side opposite to the sleeve 11 with the control plate 17 therebetween). It is formed in an arc shape. And this sleeve 1
1 and the control plate 17 are connected to the sleeve 11
By virtue of linear contact along the direction of the rotation axis, the vibration wave reflection end 7a is formed at the contact portion.

Therefore, also in the present embodiment, the standing wave s is formed between the vibration generating member 6 and the vibration wave reflection end 7a, and the same operation and effect as in the fifth embodiment can be obtained.

In the above embodiment, the control plate 17 is brought into direct contact with the sleeve 11.
As shown in (1), a spacer member 8 may be provided on the control plate 17 and the control plate 17 and the sleeve 11 may be indirectly contacted via the spacer member 8. Like the reflecting member 7 of the fifth embodiment, the spacer member 8 may have any rigidity capable of reflecting a vibration wave without absorbing vibration. For example, the spacer member 8 has a plate width of about 5 mm and a plate thickness of 0.1 mm. 2m
A metal plate of about m or the like such as stainless steel (the surface of which is coated with diamond-like carbon (DLC) is particularly preferable) or the like can be suitably used.

By providing such a spacer member 8, the vibration wave reflecting end 7a with respect to each developer passage hole 17a is provided.
Of the vibration wave reflection end 7a.
The distance between the developer and the developer passage hole array 17g can be set precisely.

[0101]

As described above, according to the present invention, by imparting the same phase vibration to each developer passage hole of the developer passage control member, each developer passage hole is uniformly vibrated. Can be done. Therefore, it is possible to remove the developer satisfactorily in all the developer passage holes. Therefore, it is possible to reliably prevent the passage hole from being blocked by the developer, and to realize stable image formation.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an image forming apparatus.

FIG. 2 is a schematic configuration diagram of a head.

FIG. 3 is a cross-sectional view illustrating a developer passage portion of a head.

FIG. 4 is a perspective view showing a control plate provided with the vibration generating member according to Embodiment 1 of the present invention.

FIG. 5 is an explanatory diagram showing a vibration mode of a vibrating body.

FIG. 6 is a diagram corresponding to FIG. 4 according to the second embodiment of the present invention.

FIG. 7 is a configuration diagram of a vibration absorber, where (a) is a top view,
(B) is a side view, (c) is a front view.

FIG. 8 is a diagram corresponding to FIG. 4 according to the third embodiment of the present invention.

FIG. 9 is a diagram corresponding to FIG. 4 according to the fourth embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a detailed configuration of an auxiliary vibration device.

FIG. 11 is a diagram corresponding to FIG. 4 according to a fifth embodiment of the present invention.

FIG. 12 is an enlarged sectional view showing the vicinity of a control plate of the head.

FIG. 13 is a sectional view of a control plate showing a standing wave.

FIG. 14 is a diagram corresponding to FIG. 12 of the sixth embodiment of the present invention.

FIG. 15 is a diagram corresponding to FIG. 12, showing a modification of the sixth embodiment.

FIG. 16 is an explanatory diagram illustrating an image forming state in a conventional image forming apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 head 2 intermediate image holding belt (image receiving means) 3 transfer device 4 fixing device 5 recording paper 6 vibration generating member (vibrating means) 11 sleeve (developer carrying means) 17 control plate (developer passing control member) 61 vibrator ( Vibration generating part) 62 Amplifier 63 Vibration transmitting member (vibration transmitting body) 64 Vibration absorbing body (vibration absorbing means) 65 Clamp mechanism 66 Auxiliary vibration device (auxiliary vibration means)

 ────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 597063831 Owneds Brygga 13 421 57 Vestro Fround a Sweden (72) Inventor Masayoshi Miura 1006 Odakadoma, Kadoma City, Osaka Pref. Matsushita Electric Industrial Co., Ltd. (72) Inventor Kitaoka Yoshitaka 1006 Kadoma, Kazuma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Masaichiro Tachikawa 1006 Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Masahiro Aizawa 1006 Kadoma, Kadoma, Osaka Prefecture Address: Matsushita Electric Industrial Co., Ltd. (72) Akira Ryuji, Inventor Akira 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Masahiko Hashimoto 3-1-1, Higashi-Mita, Tama-ku, Kawasaki City, Kanagawa Prefecture Matsushita Giken Co., Ltd. F-term (reference) 2C162 AE09 AE12 AE25 AE31 AE47 AE69 AE74 AH03 AH14 AJ07 AJ24 CA03 CA12 CA24 2H029 DB04 DB05

Claims (12)

[Claims] 1. A developer carrying means for carrying and transporting a developer, and at least one row of developing means provided between the developer carrying means and the image receiving means, wherein a plurality of developer passage holes are arranged. A developing device having a row of developer passage holes, wherein the developer conveyed by the developer carrying means is controlled to fly so as to pass through a predetermined developer passage hole and adhere to the image receiving means in accordance with an image signal. An image forming apparatus comprising: a developer passage control member; and a vibration unit configured to vibrate the developer passage control member so as to detach the developer adhered to the developer passage control member. Is an image forming apparatus configured to apply vibrations of the same phase to respective developer passage holes of the developer passage control member. A vibrating means extending parallel to the row direction of the developer passage hole row and fixed to the surface of the developer passage control member; and a vibrating means parallel to the row direction so as to overlap the vibrating plate. A piezoelectric element that extends and is fixed to a surface of the vibration plate opposite to a contact surface with the developer passage control member; a regulating body that regulates expansion and contraction of the piezoelectric element in the column direction;
The image forming apparatus according to claim 1, further comprising: 3. A developer carrying means for carrying the developer while carrying it, and at least one row of developing means provided between the developer carrying means and the image receiving means, wherein a plurality of developer passage holes are arranged. A developing device having a row of developer passage holes, wherein the developer conveyed by the developer carrying means is controlled to fly so as to pass through a predetermined developer passage hole and adhere to the image receiving means in accordance with an image signal. An image forming apparatus comprising: a developer passage control member; and a vibration unit configured to vibrate the developer passage control member so as to detach the developer adhered to the developer passage control member. A vibration transmission body extending in parallel with the row direction of the developer passage hole row and fixed to the surface of the developer passage control member; and from one end of the vibration transmission body to the other end, parallel to the row direction. To generate an oscillating wave that travels The vibration and the vibration generating portion for vibrating at one end of the transmission member, the image forming apparatus vibration wave of said vibration transmitting member in the and a vibration control unit for controlling the vibration so that the non-constant standing waves in. 4. A vibration control section is provided at the other end of the vibration transmission body so that the vibration applied to one end of the vibration transmission body from the vibration generation section is absorbed at the other end of the vibration transmission body. The image forming apparatus according to claim 3, further comprising a vibration absorbing unit. 5. The vibration control section includes a clamp means for sandwiching the other end of the vibration transmitting body while shifting the clamp position so as to change the reflection position of the vibration at the other end of the vibration transmitting body with time. The image forming apparatus according to claim 3. 6. The image forming apparatus according to claim 3, wherein the vibration control unit includes an auxiliary vibration unit that minutely disturbs the vibration from the vibration generating unit in the vibration transmitting body. 7. The developer passage control member includes a developer passage hole formed on a side opposite to the vibration transmission body across the row of developer passage holes so as to form a reflection end for reflecting vibration from the vibration transmission body. The image forming apparatus according to claim 1, wherein the image forming apparatus is in line contact with the developer carrying unit in parallel with a row direction of the row. 8. The image according to claim 7, wherein spacer means is provided at a reflection end of the developer passage control member, and the developer passage control member is in contact with the developer carrying means via the spacer means. Forming equipment. 9. The image forming apparatus according to claim 8, wherein the spacer means extends along the developer passage hole array. 10. The distance L1 between the developer passage hole array and the reflection end is defined as L1 with respect to the wavelength λ of the vibration wave in the developer passage control member in the direction orthogonal to the row direction of the developer passage hole array. The image forming apparatus according to any one of claims 7 to 9, wherein the image forming apparatus is set so as to satisfy <λ / 2. 11. A vibrating means comprising: a vibration wave in a direction orthogonal to a row direction of a row of developer passage holes in a developer passage control member, wherein a vibration end is a node at a reflection end and an antinode of the row of developer passage holes. The image forming apparatus according to any one of claims 7 to 10, wherein the image forming apparatus is configured to apply vibrations that generate waves. 12. A distance L2 between the vibration transmitting body and the reflection end.
Is set such that L2> λ / 4 with respect to the wavelength λ of the vibration wave in a direction orthogonal to the row direction of the developer passage hole row in the developer passage control member. An image forming apparatus according to claim 1.